This proposal is submitted in response to NIH Funding Opportunity Connectome Related to Human Disease (U01) and in response to NIMH's priority/disease area of interest mood and anxiety disorders. This is a collaborative effort among researchers at the Massachusetts General Hospital (MGH), Massachusetts Institute of Technology (MIT), McLean Hospital, Boston University, and the Human Connectome Project (HCP) at Washington University in St. Louis. We believe that the combination of (1) state-of-the art MRI technology and methods at the MGH Martinos Center for Biomedical Imaging, (2) an active collaboration with the HCP to validate neuroimaging harmonization, (3) a Boston-wide consortium of experienced and expert clinical researchers, and (4) a transdiagnostic focus across the anxiety and depression spectrum can deliver a high- quality dataset that meets the specification of the Funding Opportunity. We propose to focus on an area of great clinical need and public health implication: better understanding of psychiatric disorders in adolescence. We target anxiety and depression as diseases that affect many adolescents across multiple traditional psychiatric diagnoses, that are strongly associated with two leading causes of death in adolescents and young adults (suicide and substance-abuse related accidents), and that are understood to frequently have developmental roots leading to lifelong psychiatric disorders. Our research approach is guided by two principles (1) careful adherence to HCP protocols so as to develop large-scale, integrated, and growing data sets available to the scientific community, and (2) a research approach aligned with two constructs from the NIMH Research Domain Criteria Project (RDoC), specifically: (a) the ?Acute Threat/Fear? construct, which is associated with atypical structure and function in specific neural networks, especially amygdala, orbitofrontal cortex (OFC), and ventral medial prefrontal cortex (vmPFC); and (b) the ?Reward Prediction Error? construct, which is associated with OFC, ventral striatum, and the midbrain ventral tegmental area. Across four years we aim to (1) operationalize MRI data collection and behavioral characterization that is harmonized and validated with the Human Connectome Project (HCP); (2) recruit and characterize clinically and behaviorally, 225 adolescents ages 14-15 with and without anxiety and/or depression (180 patients, 45 controls); and (3) perform and analyze HCP imaging with participants. We hypothesize that greater activation in the amygdala-OFC circuit will correlate with more severe scores on measures of fear, and that lesser activation of the striatal-OFC circuit will correlate with more severe scores on measures of reward-error expectancy. We will also (a) examine whether neuroimaging analyses are enhanced with artifact-detection tools and physiological aliasing correction that are publicly available and could be integrated with the HCP, and (b) create an age-specific human tract atlas and tools for automated reconstruction of white-matter tracts involved in the above circuits, which will also be made publicly available.